In-situ tracking conformational changes of biomolecules using chiral optical force microscopy
Yang Zhao, Ph.D.
Assistant Professor
Department of Electrical and Computer Engineering
Department of Bio Engineering (by Courtesy)
University of Illinois at Urbana-Champaign
Chirality is fundamental to many physical, chemical, and biological systems, impacting processes as diverse as pharmaceutical-cell interactions to the evolution of species. Measuring molecular chirality is especially important to synthesize chiral compounds, study enzymatic interactions, and understand dynamic protein folding and DNA hybridization. Current methods to measure molecular chirality rely on ensemble techniques such as circular dichroism spectroscopy. However, these techniques require large analyte concentrations and relatively long integration times. Measuring molecular chirality at the few-to-single molecule level and in real time remains an outstanding challenge.
In this talk, I will discuss how light can be sculpted with engineered nanostructures to enhance chiral light-matter interactions. With these nanostructures, we have developed metamaterial biosensors and optical force microscopes to detect and visualize molecular chirality with high sensitivity and resolution. Specifically, I will discuss a nanostructure-enhanced atomic force microscope to image chiral optical forces with nanometer spatial resolution and piconewton force sensitivity. We use this technique to measure the chirality of DNA molecules, approaching the single-molecule regime. These studies provide a foundation for new sensing and imaging techniques at the single molecular to cellular level in-situ and in real time.
Bio: Yang Zhao is an assistant professor at the University of Illinois, Urbana-Champaign, Department of Electrical and Computer Engineering. She is affiliated with the Holonyak Micro and Nanotechnology Laboratory and has a courtesy appointment with the Department of Bioengineering. Her lab develops nano-optical and nanophotonic tools including metamaterials and optical force nanoscopy, and applying them for imaging and sensing biomolecules. Prof. Zhao received her PhD degree from the University of Texas at Austin, where she studied with Professor Andrea Alù in the Department of Electrical and Computer Engineering on optical metasurfaces to manipulate light-matter interactions at the nano-scale. She received her postdoctoral training with Professor Jennifer A. Dionne in the Department of Materials Science and Engineering at Stanford University. At Stanford, her research focused on developing plasmonic optical tweezers for directly manipulating molecules and optical force spectroscopy tool for mapping three-dimensional chiral force-fields.
